The Belfast Telegraph UK says the British star is on team X-Tina to give the Ecuadoran-American singer the support she needs following Aguilera’s recent weight gain. Aguilera, responding to critics, has said she loves her fuller shape.

“Now Adele has become Christina's secret weight mentor, calling her regularly to dish on dieting horror stories and offer advice on clothes that best flatter the fuller figure," a source said, according to the website.

"She's really helped Christina improve her self-esteem."

The publication says that Aguilera and Adele are close friends and that the Grammy Award-winning singers “joke all the time about how they're forming a fat girls singing club to support other musicians with weight issues.”

The recent news comes as photos of Aguilera surfaced on the web of her in a revealing Halloween costume, Us Weekly is reporting.